Thirty subjects with HIV infection and CD4 lymphocyte count less than 300 cells/mm3 will participate. All subjects will receive 200mg of intravenous itraconazole solution twice daily for two days and then once daily for five additional days. Subjects will then be randomized to receive 200mg twice daily or 200mg once daily oral itraconazole capsules for an additional 28 days. Blood samples will be obtained prior to and at 15 and 30 minutes and 1,2,4,6,8, and 11 hours after the end of first i.v. dose. Blood sampling on day 7 following the last i.v. dose will be identical to day 1 with an additional sample at 23 hours. Twelve-hour urine collection for creatinine clearance and hydroxpropyl-B-cyclodextrin excretion will be performed during and after the day 1 and day 7 infusion. Blood samples will be obtained prior to and following a single oral dose at the completion of 28 days of oral dosing. Additional blood samples will be taken prior to administration of each i.v. dose and weekly prior to the morning dose during the oral dosing phase of the study. Twelve-hour urine collection for creatinine clearance will be performed during and after the day 36 dose.